For years, the metal can manufacturing industry has been utilizing a resuable paperboard carton to ship their heavy, metal can ends. Due to the heavy weight of the metal can ends, these cartons have their top and bottom flaps sealed with tape to securely keep the can ends therein. Once the cartons arrive at their destination, they are unpacked by removing the tape from the carton, and these cartons are reshipped back to the can's manufacturer to be reused. However, when the tape is ripped from the carton, it sometimes tears part of the liners from the carton and therefore weakens it. This has an adverse effect on the number of times an individual carton can be reused. In addition, the tape utilized and the labor to apply the tape is rather expensive.
While there have been self-locking cartons designed in the past, they have not been strong enough to hold the weight of the heavy, metal can ends and tend to fall apart.